SMTP is the abbreviated form of Simple Mail Transfer Protocol, extensively used by the servers for sending emails. Neither sending or receiving emails was a great problem even two decades ago. With help of an SMTP mail server, any body could send emails across the net. An unavoidable but unexpected spanning problem emerged and it posed a threat to both sending and receiving email. As a result Internet Service Providers made some significant changes in their functioning to overcome this spamming problem. Verifying that the sender of an email is not a spammer but a genuine owner is a way to sort out this junk email problem, commonly known as spamming problem. The verification is done by checking if the person is connected to an authorized ISP network.

Email senders experience several SMTP mail sending problems. The most common of them is encountering the 'Bad login' error. Such problem may occur due to the mismatch between Username and Password. When you are notified about unsuccessful login, the first step is to check your hosting account. In case, the email account has not been successfully created, the error message will continue to generate whenever you try to log in. The next step to eradicate the SMTP mail problem is to verify if you have input in the correct username. As long as the correct username is not given, you will experience the bad login problem. Users often forget the password especially if they have several email accounts. One method to solve this issue is going to Cpanel or Plesk and find out if you have provided the correct password for the specific username or not.

Another irritating SMTP mail problem is when the 'Server not found' error flashes on the screen. If you encounter this problem, first check whether the internet connection has been set up rightly or not. Internet connection is the must-have requirement to have an access to the SMTP service provider. If you are sure that there is nothing wrong with the internet connection, then get your email client setting checked. Such checking is advised to ensure that you are using the correct SMTP mail server. An SMTP server is generally recognized as mail.userdomain. But there are many Internet Service Protocols that mandate the use of their own SMTP mail servers. So, know the actual requirement of your ISP technical support.

If an individual is using a newly registered domain name, he may encounter the same ' Server not found' message. The reason is that the domain does not propagate on the net as soon as the new registration is done. So, indicating your client to mail.userdomain will not work at this moment and you have to bear this problem at least one day. Another SMTP mail sending problem is when an immediate message 'Mailbox full' in response to your email pops up on the screen. It is not a problem of your SMTP service provider. The message simply indicates the address box of your receiver is filled up to the brim. In such a case, you can only advise him or her to delete some of the messages.